1. Field of the Invention
The present invention is directed toward an apparatus for quickly configuring a jack to raise a load from its rest position. In particular, the present invention provides a jacking mechanism that telescopes from a locked, elevated position to a locked, lowered position in order to situate the jacking mechanism for raising a load. Correspondingly, the present invention provides a jacking mechanism that telescopes from its locked, lowered position to its locked, elevated position for stowing the mechanism between uses.
2. Background Information
The use of jacking mechanisms, specifically those used in combination with trailers, is well known in the art. Furthermore, jacks heretofore devised and utilized are known to consist of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art, which has developed for the fulfillment of countless objectives and requirements.
The prior art for jacking mechanisms include U.S. Pat. Nos. 5,184,839, 4,842,252, 4,078,774, and 4,053,174. While these devices fulfill their respective, particularly claimed objectives and requirements, the aforementioned prior art fail to disclose a telescoping jacking mechanism, as claimed in the present invention.
Trailer jacks are a necessity in many industries, including the agriculture, commercial and recreational industries. Jacks are needed to raise and lower trailers with respect to their towing counterparts. Furthermore, these devices must offer support of a trailer load and provide lateral stability to the trailer, while in use.
Two types of trailer jacks predominate the industry, swivel jacks and hydraulic jacks. Swivel jacks operate by cranking a handle to turn a screw which raises and lowers the jack. Hydraulic jacks use hydraulic pressure to raise and lower the jack. Hydraulic jacks may be manually operated or motorized.
Traditional swivel jacks are cumbersome to use and have substantial drawbacks. Foremost, is the time it takes to manipulate the jack from its elevated position to its lowered, ground-engaged position. When a traditional swivel jack is initially engaged with a trailer, the “foot” of the jack is at an extremely elevated or stowed position. In fact, enough space must exist between the foot of the jack and the ground to be able to move and manipulate a trailer without the jack being in a position to contact an obstruction, which would damage the jack. From this extremely elevated position, the jack foot must be hand-cranked all the way to its ground engaged position, prior to even beginning the lifting of the trailer. Thus, raising or lowering the trailer jack requires a significant number of revolutions, in turn, requiring a significant amount of time and effort each time the trailer is engaged or disengaged from a tow vehicle.
By comparison, traditional hydraulic jacks include significant advantages over traditional swivel jacks. Manually operated hydraulic jacks require a lever which must be either rotated or pumped to create the necessary hydraulic pressure to move the jack foot and raise the load. Therefore, the manually operated hydraulic jack suffers from the same substantial impediment as the swivel jack. That is, the time and effort it takes to move the jack foot from its elevated, stowed position to its lowered, ground-engaged position is significant. In contrast, motorized hydraulic jacks operate much more quickly, but they suffer from another drawback, which is the significantly increased cost and complexity of the motorizing device itself.
In view of the limitations associated with the prior art, a substantial need exists for a jack that is affordable and can readily convert from a support position to a stowed position. Applicant's invention, through a novel combination of component pieces, provides such a jack mechanism.